1. Field of the Invention
The present invention relates to a motor control system, particularly to a real-time responsive motor control system.
2. Description of the Related Art
Electromechanical control technology plays an important role in daily living; it facilitates rotary and linear motions required for applications ranging from less-sophisticated household appliances to sophisticated electronic systems and computers. With the increase in the scale and the complexity of electromechanical systems, more sophisticated electromechanical control technology is desired to meet the performance, safety and power efficiency requirements. Small-size electromechanical systems are usually employed in applications, which require highly precise electromechanical control. Large-size electromechanical systems, such as a robot, are usually employed in applications, which require very complex electromechanical control in which real-time responsiveness is very critical.
An example of the conventional electromechanical control systems may be understood with reference to FIG. 1, which is a block diagram schematically, showing a conventional control system of a brushless DC motor. The conventional motor control system comprises: a brushless DC motor 10, a Hall sensor 11, an error-detection circuit 12, and a central microcontroller device 13. The central microcontroller device 13 further comprises: a phase-processing unit 131, an error-processing circuit 134, a PWM (Pulse Width Modulation) generator 133, and a central microcontroller 132. In the brushless DC motor 10, a motor switch module 101 controls the turn-on and turn-off of a motor coil module 102. When the motor switch module 101 turns on the motor coil module 102, the Hall sensor 11, which is disposed near the motor coil module 102, detects the phase variation of the motor coil module 102 and generates phase signals corresponding to the phase variation. The signals corresponding to the phase variation are sent to phase-processing unit 131 to be processed thereby, and the resultant output signals are sent to the central microcontroller 132. The error-detection circuit 12, which is coupled to the brushless DC motor 10, detects error signals of the brushless DC motor 10 and sends the error signals to the error-processing circuit 134. The error-processing circuit 134 processes the error signals and sends the processed error signals to the central microcontroller 132. Based on the received phase signals, the received error signals, the timing signals from a timer 135 and the data from a sinusoidal lookup table 136, the central microcontroller 132 performs calculation, comparison, and analysis to work out the amended voltage and current signals needed by the motor coil module 102. The signals worked out by the central microcontroller 132 are sent to the PWM generator 133. The PWM generator 133 transforms the input PWM signals into corresponding PWM waveforms and sends the PWM waveforms to the motor switch module 101. Then, the motor switch module 101 utilizes the PWM waveforms to control the motions of the motor coil module 102.
In the abovementioned control system of a brushless DC motor, all the signals, instructions, and interruptions are processed by only a single microcontroller, which may be easily overloaded. As the microcontroller is burdened with a lot of signals, instructions, and interruptions simultaneously, the microcontroller may be unable to timely process phase detection and speed calculation to output accurate motor control signals. Further, to meet different motor control theory requirements, the hardware configuration of such a control system usually needs to be greatly modified for different applications. In this situation, not only the hardware design becomes complicated but the cost is also considerably high. Meanwhile, the adaptability of the motor control systems is pretty limited because each type of motor needs its special control system.
Accordingly, the present invention proposes a real-time responsive motor control system to solve the abovementioned problems, wherein the motor control parameters, such as phase and rotation speed, can be more precisely controlled; a modularized hardware design simplifies the architecture of the motor control system; and the adaptability of the motor control system is greatly enhanced due to flexible software programming. In addition to the simpler hardware and more flexible software, the motor control system of the present invention can focus its core function on the theoretical calculation for motor control. Thus, the present invention reduces cost, simplifies hardware design, and provides more precise motor control to optimize the motor system.